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chlorine at night, need to drain pool?

I just started taking care of my own pool, to decrease pool service expenses. Owned a pool for a total of 5 months only. A pool service took care of the pool until now. So everything is NEW to me! I will read all the great info, but here are some urgent issues.

I just got the TF100 test kit. Here are the results:

FC 6
CC 0
TC 6
pH 7.8
T/A 110
CH 600
CYA 110

Because I was thinking about converting the pool to salt water, to save money in the long run without spending a lot of time to maintain the pool (a bit scared of the task, really). a pool guy came over and took a water sample. He said everything is fine except
phos 200
TDS 3600, but salt is 2500, so real TDS is 1100
CYA was 100

So my questions are:
According to the pool calculator, FC should be above 8. If I add bleach at night to minimize UV loss, how long do I need to keep the pump running? Right now the pump is only running from 9:30-4pm. Do I need to turn it on again to circulate chlorine or is it more energy efficient to just add it during the day while the pump is running. The previous pool guy said pump needs to be run only during the hottest time of the day. Anything pump run time at night is only additional? Won't that increase cost?

Does the pool need to be drained? CYA and CH high. Water cost a lot here. It's winter, should I wait until summer to drain pool and start fresh? The bottom line here is to minimize cost.

Re: chlorine at night, need to drain pool?

So my questions are:
According to the pool calculator, FC should be above 8. If I add bleach at night to minimize UV loss, how long do I need to keep the pump running?

Welcome to TFP!

I think you have a good feel for the numbers. Free Chlorine (FC) should be at or above 5.5 ppm if you have SWG (that's 5% of CYA 110) or 8 ppm without. If you reduce the CYA you can reduce chlorine level.

Right now the pump is only running from 9:30-4pm. Do I need to turn it on again to circulate chlorine or is it more energy efficient to just add it during the day while the pump is running. The previous pool guy said pump needs to be run only during the hottest time of the day. Anything pump run time at night is only additional? Won't that increase cost? Does the pool need to be drained? CYA and CH high. Water cost a lot here. It's winter, should I wait until summer to drain pool and start fresh? The bottom line here is to minimize cost.

Winter is coming on and even in Irvine the "hottest time of the day" is not particularly hot. Your interest is in decreasing cost, so why run the pump additional hours? Add the chemicals in the late afternoon during the day. If you have an algea outbreak it's more difficult to manage at very high CYA. In addition the high CH affects water balance. You'll want to run all of these numbers in the Pool Calculator to check.

So, I'd recommend draining about 10-15% of your pool, remeasuring CYA and CH to get a baseline. 100 or 110 CYA is a bit high. A more problematic number is 600 Calcium Hardness. You could just wait until CYA goes down on its own. But be prepared to wait a very long time (less, if you vacuum to waste). The calcium isn't going anywhere, either, until some of the water is drained. It was probably introduced by Cal-Hypo tablets by the pool service. Chlorine (liquid bleach) would have added none of the undesirable extras. If this was my pool, I'd do at least a partial drain and pay the water bill. Peace of mind. Also, if through partial draining you can get CYA down to 80, then your chlorine level can drop, too... from 8 ppm to 4-6 ppm.

The pool guy mentioned to add phos remover.

Almost no one here bothers with trying to reduce phosphates. If you have proper chlorine level, algae is much less likely.

Re: chlorine at night, need to drain pool?

1. How did your salt content get to 2500? Did you add salt?

2. Disregard phosphates.....especially if you want to save some money....they're irrelevant.

3. Keep in mind that chlorine must be kept in your pool at all times to avoid algae. It is efficient to add it at night but it needs to be kept at a residual level to keep your pool sanitized and prevent algae.

4. As you know, your CH and CYA are too high. If you will keep you chlorine up as the water cools (and you enter your rainy season) I think you can get by with allowing rainwater to dilute your CYA and your CH. Can you direct a gutter into the pool to further help dilution?

5. The best bet is to drain about a third and get both your CH and CYA manageable.....half would be better. That's your call to make. If you keep your pH monitored carefully (to avoid scaling) and keep your FC up (to avoid algae), you may well get by but your on the borderline for some upcoming problems without reducing those two parameters.

6. This time of year in your climate, I would consider about a 6-8 hour run time as minimum on your pump. AS it gets cooler, I think you can easily cut it back to four but don't underestimate the helpfulness of good circulation and filtering.

On a side note, trust your own testing (and the advice on this forum). Phosphates is a misleading parameter and usually only ends up reducing your wallet and not much else.

On another side note, telling us the city and state in which you live is incredibly helpful.......other posters take note

Re: chlorine at night, need to drain pool?

Thanks so much for your help. To answer a couple of questions:
salt: I didn't add any salt. I have no idea how it got there.
rain dilution: It really doesn't rain much even in the winter here in Southern CA. So I have no other option but to drain the pool partially.
Just want to make sure these are the goals I'm looking for using the calculator (suggested goal levels for bleach and plaster/ pebble tec):

That brings up another question:
How do I drain the pool? I can rent a pump for $35/day or have a pool service do it for $100 with chemicals included. Is it something that can be managed by a newbie? Do I need to buy any other supplies besides renting the pump? Do I need to treat the pool water before it drains into sewage? Thanks so much!

If you can do this, that will help you reduce CH, CYA and salt in one pass.

That brings up another question:
How do I drain the pool? I can rent a pump for $35/day or have a pool service do it for $100 with chemicals included. Is it something that can be managed by a newbie? Do I need to buy any other supplies besides renting the pump? Do I need to treat the pool water before it drains into sewage?

You can probably buy a pump that works with a garden hose at Home Depot or Lowes for $60-$90 -- or just rent one for a day. Beware of any chemicals a pool service wants to add in their $100 package... depending on the additives, you might end up back where you started!

Don't know regulations in your area so can't offer authoritative advice to you on this, but I don't think you'd need to treat the water before releasing it to the curb. (Check city regulations first!) Where I live, you can drain your pool to either sewer or storm drain. I do the latter.

Re: chlorine at night, need to drain pool?

1. Do your draining in two steps of about 30% of your water each time. That should get your CYA down around 50 which is ideal and your CH around 300......ideal as well.

2. Your TA is fine right where it is.

3. That's weird about the salt. That level of salt does not occur naturally in pools so someone put salt in some time ago, It won't hurt anything but I think it's probably better that it will be diluted down when you start to drain and refill.

Re: chlorine at night, need to drain pool?

added a little more than 100 oz of 6% bleach yesterday. FC went from 6 to 6.5 only! According to the pool calc, it should have gone up to 8. Should I add the rest of the 182oz chlorine jug before I can get to draining the pool? Thank you.

I didn't not see a valve that said vacuum to waste. Where is it typically found?

Re: chlorine at night, need to drain pool?

Originally Posted by irvinenewbie

added a little more than 100 oz of 6% bleach yesterday. FC went from 6 to 6.5 only! According to the pool calc, it should have gone up to 8. Should I add the rest of the 182oz chlorine jug before I can get to draining the pool? Thank you.

If you tested and measured correctly (ditto with numbers entered into Pool Calculator) then something is consuming the chlorine... it could be oxidizing waste (leaves, debris, dirt, etc) or there is some algae in the water. If this was my pool, I would drain first, refill then chlorinate.

I didn't not see a valve that said vacuum to waste. Where is it typically found?

Assuming that you vacuum the pool (using suction) and don't rely on a pressure-side automatic cleaner there should be an opening at or near the equipment pad from which you can extract the water. I've never tried this, but you might be able to use the filter drain plug for this purpose (first, ask someone else here on the forum to confirm whether this works!)

Originally Posted by irvinenewbie

CH of tap water is 80, pool water is 600. What should I put in the calculator as "now level", 600, or 680? planning to partial drain and refill.

Depends of course on what you're trying to accomplish... I would focus on the pool water... put the test result number of the pool water (CH 600) in the "now" and enter a more reasonable (recommended) figure as Target level.

What's the reason of doing the partial drain in 2 steps? test CH and CYA after half of it is drained, then recalculate how much more water needs to be drained?

Not sure why duraleigh recommended a 2 step process; perhaps this is a better approach than doing it all at once but I'm not sure.

Re: chlorine at night, need to drain pool?

What's the reason of doing the partial drain in 2 steps?

It's simply a general precaution. 60% will likely uncover the floor of the shallow end which you would never want to do in a liner pool and there has been some discussion on here about plaster floors not being uncovered but I don't think there's much to that.

With your plaster pool, you could probably do it in one shot but it doesn't give you an opportunity to adjust. If you did a 30% refill, stopped and tested, you would likely be able to come out just about right on your parameters when you did the second refill. You may find that you only need to do 20% the second time or perhaps 40%.

Re: chlorine at night, need to drain pool?

Before draining, you should check with the local water authorities about rules for where the water goes. In some places (e.g. SF Bay Area) you must drain to the sewer, not the street or ground. I don't know what the rules might be in SoCal.

If you are intending to install an SWG, as DBfan187 suggested and from what I've seen here, it should be for convenience rather than cost savings. Also you would not want to drain as much, because with an SWG your CYA ought to be up in what, the 70-80 range? Also draining will reduce your salt, and you'd have to replace that as well. If you intend to use bleach, then lower levels of CYA will help, and you'd want to replace more water as others have suggested.
--paulr

Re: chlorine at night, need to drain pool?

Thank you very much for all your help so far. I started the draining process this morning. The shallow end of the pool is 3ft, deep end is 5 ft. Please see pictures in signature for odd pool shape. In the past 4 hours or so, the water level has decreased by 15 inches. I was told the sump pump flow rate is 1000gal/hr, but not confirmed. But it seems water is draining much faster than that.

1)How do I know when the volume is drained by 50%? How do I calculate how many inches the water level should decrease?

2)There are some brown stains at the very deep end of the pool near the wall, which may be algae. Do I do the whole shock process after the pool is refilled? Or can I cheat and pour bleach over that spot (with some residual water since the pool is only going to be drained 50%) and hopefully that concentrated chlorine will kill it. It's minimal. Brushing with the regular brush doesn't do anything. It's actually been there for at least a week.

Re: chlorine at night, need to drain pool?

Originally Posted by irvinenewbie

Thank you very much for all your help so far. I started the draining process this morning. The shallow end of the pool is 3ft, deep end is 5 ft. Please see pictures in signature for odd pool shape. In the past 4 hours or so, the water level has decreased by 15 inches. I was told the sump pump flow rate is 1000gal/hr, but not confirmed. But it seems water is draining much faster than that.

1)How do I know when the volume is drained by 50%? How do I calculate how many inches the water level should decrease?

You can guess by averaging the total depth of your pool. E.g., if you have more or less equal sections of 3', 4,' 6' etc you could add these together divide by number of depths, then multiply by inches. 3 + 4 + 6 = 13 / 3 = 4.33 (avg ft) * 12 = 52 inches

1/2 of your pool would be roughly 26" below your water line (usually mid-tile.)

2)There are some brown stains at the very deep end of the pool near the wall, which may be algae. Do I do the whole shock process after the pool is refilled? Or can I cheat and pour bleach over that spot (with some residual water since the pool is only going to be drained 50%) and hopefully that concentrated chlorine will kill it. It's minimal. Brushing with the regular brush doesn't do anything. It's actually been there for at least a week.

If the stains appeared all at once only a week ago, it's very likely that it is algae. But you also mention that brushing doesn't do anything.... not sure what you mean by that. Consider testing it for mineral stain (with vitamin C tablet - see pool-school/metal%20stains). If it's algea you can treat it topically with liquid chlorine while the water is low, but would recommend that once you refill the pool and circulate, retest the water to determine CYA level and then begin the shock process.

Re: chlorine at night, need to drain pool?

Thanks for your reply. I should ask the question more clearly:
how many inches of water should be drained to decrease the volume by 50% (or 10.5K gallon)? given: shallow end at 3ft, deep end at 5ft, total volume 21K gal. drained 14-15 inches from the top so far in 4 hours. would the shallow end be empty when it's half drained? so there will be 2 feet of water left at the deep end? something to that effect. i ask b/c I don't want to over drain and re-add chemicals and waste water. at the rate it's going, it's seems more than half is drained already!

brushing did not change the appearance of the stain. didn't go away. didn't move. thanks for the link about stains.

after refilling, how long do I need to circulate the water before testing?

how long does it take to refill 10K gal? I don't want to wake up to an overflowed pool.

Re: chlorine at night, need to drain pool?

Originally Posted by irvinenewbie

Thanks for your reply. I should ask the question more clearly:
how many inches of water should be drained to decrease the volume by 50% (or 10.5K gallon)? given: shallow end at 3ft, deep end at 5ft, total volume 21K gal. drained 14-15 inches from the top so far in 4 hours. would the shallow end be empty when it's half drained? so there will be 2 feet of water left at the deep end? something to that effect. i ask b/c I don't want to over drain and re-add chemicals and waste water. at the rate it's going, it's seems more than half is drained already!

I was revising my answer while you posted this... please read my better explanation for determining this (above.)

brushing did not change the appearance of the stain. didn't go away. didn't move. thanks for the link about stains.

after refilling, how long do I need to circulate the water before testing?

Well, to be sure everything was mixed fairly well, I'd guess an hour would be good. Depends a bit on your pool (how many returns etc.) But I don't think you need to recirc over night unless you're looking for maximum precision of test results.

how long does it take to refill 10K gal? I don't want to wake up to an overflowed pool.

Depends on how many hoses you use, their diameter, water pressure etc. You can probably start filling then estimate the remainder after it's refilled a couple of inches.